Structural surfaces



June 1, 1965 w. MCCAULEY I 3,186,522

June 1, 1965. s. w. MOCAULEY 3,186,522

STRUCTURAL SURFACES Filed Feb. 27, 1963 2 Sheets-Sheet 2 F\G.3A {Em INVENTOR GEORGE w. MC CAULEY ATTORNEYS United States Patent 3,186,522 STRUCTURAL SURFACES George W. McCauley, 64 Fuller St., Waban 68, Mass. Filed Feb. 27, 1963, Ser. No. 261,384 16 Claims. (Cl. 189ll) The present invention relates to post-stressed continuous one-directional, two-directional and three-directional structural surfaces, and their assembly.

Whereas most known structural surfaces are dependent upon the primary use of compression as the mode in which induced load is propagated, the present invention is directed to the dispersion of an applied structural load over the structural span in terms of a geometric reduction of impetus by primary use of tension. As a result, longer span structures than have hereto-fore been considered feasible are rendered possible and economically practical. Although the present invention is contemplated as having one of its principal applications to long span structures, it is not intended to be limited to such applications. For purposes of illustrating the concept and structure of this invention, the herein described specific embodiment is a hemispherical dome structure. However, the invention is equally applicable to other shapes, such as arcuate surfaces, arches, flat surfaces, and compound and complex curvatures of practically any desired design.

The structural surface of the present invention may be considered to be a system formed of two networks, the first network being compressional in mechanical function with the second network being counterpoised as a tensional function, the two networks being interconnected and interrelated in force reactive relationship in such a counterpoised manner as to distribute a load over the structural span primarily in terms of tension. To this end, the compression network is comprised of a plurality of interconnected polygonal cells forming a continuous spinal structure over the extent of the span. A plurality of tension rods are interposed in a counterpoised manner with each polygonal cell. The tension rods of each cell are joined together at the centrum of the cell, and radiate therefrom to the perimeter or bounds of the cell, where they are fastened at their respective positions in a manner as to restrain the cells from bulging or buckling outwardly from the center as would be the normal tendency under compressive load. The assembled series of interrelated tension rods thus form the counter-poised tension network. The spinal compression network structure when completed includes means for post-stressing the cells into compression by a determined amount, and placing the tension rods in tension, thereby raising the resonant quality of the structure, and improving its response rate, and effectively distributing the structural load over the span primarily by means of tension. Accordingly, the load is carried primarily by the tension rods and not the compression network.

It is therefore one object of the present invention to provide post-stressed continuous one-directional, two-directional and three-directional structural surfaces.

Another object of the present invention is to provide for the dispersion of an applied structural load over a structural span in terms of a geomertic reduction of impetus by primary use of tension.

Another object of the present invention is to provide a structural span comprised of interreactive compression and tension networks, wherein the structural load is primarily carried by the tension network.

Another object of the present invention is to provide a spinal structural span comprised of inter-connected poly onal cells, wherein the structural forces on said spinal structure are converted from compression forces to tension forces.

p 3,l86,522 Patented June 1, 1965 Other objects and advantages of the present invention will become apparent to those skilled in the art from a consideration of the following description of one exemplary specific embodiment of the present invention, had in conjunction with the accompanying drawings, in which like reference characters refer to like or corresponding parts, and wherein:

FIG. 1 is a schematic top plan view of a hemispherical structural surface embodying the present invention;

FIG. 2A is an exploded perspective view, and FIG. 2B is an assembled perspective view, of a vertex cluster of polygonal cell walls, being enlarged detailed views of the portion of FIG. 1 encircled in dotted lines and labeled FIG. 2;

FIG. 3A is an exploded perspective view, but FIG. 3B is an assembled sectional view, of a central tension rod clamp or clevis and a tension rod cluster associated therewith, being enlarged detailed views of the portion of FIG. 1 encircled in dotted lines and labeled FIG. 3;

FIG. 4A is an exploded perspective view, and FIG. 4B

is an assembled sectional view, of an assembly of a cell wall and associated tension rods, being enlarged detailed views of the portion of FIG. 1 encircled in dotted lines and labeled FIG. 4;

FIG. 5 is an enlarged detailed plan view of that portion of the structure schematically shown in FIG. 1 and included within the dotted lines labeled FIG. 5 and FIG. 6 is a cross sectional view of the structure shown in FIG. 5, and taken along the line 6 -6.

The two systems or networks of the structural surface of the present invention are indicated in the schematic hemisphere of FIG. 1. The compression system of polygonal cells is there designated by heavy lines, while the tension system is indicated by light lines. The compression system comprises a spinal structure of equilateral triangular cells 12 formed by bounding panels 10, joined at their vertices 11. An assembly of three tension rods 14 is associated with each cell 12, and compirses a clamp or clevis 13 located in the center of the respective cell, which secures the ends of the three tension rods 14. Each tension rod passes from the center clamp to the center of a respective panel 1t), thence through the panel, and mounts an abutment to the panel on the far side thereof, in a manner to restrain the panel from buckling outwardly away from the central clamp 13 of the particular tension rod, but leaving the panel free to buckle in the opposite direction, toward said central clamp, by sliding over the tension rod and away from the abutment. However, since each bounding panel 19 of each cell 12 is common to the adjacent cells (except of course the terminal walls of terminal cells of the structure), and since each cell 12 is provided with a central clamp 13 and associated tension rods 14 coupled to respective bounding panels 10, the buckling of a panel either inwardly or outwardly relative to a given central clamp is restrained by tensioning one or the other of the two rods 14 in opposing abutment therewith.

Thus it will be generally appreciated that with a struct-ural system as illustrated in FIG. 1, the structural compressional load imposed upon the cell panels 10 stresses them in a manner to compress the area bounded by each cell 12, and causes the triangle bounding walls 10 to tend to buckle or curve toward a circular configuration. However, this compressional force is taken up in the tension rods 14 which restrain the cell panels 12 from buckling.

' Accordingly the load is transmitted and dispersed throughare assembled in radiating cluster fashion, as best shown in FIGS. 2A and B, with the ends of panels 1t one panel being seated between each adjacent pair of clips; and a bolt or other fastening means 21A secures each adjacent pair of clips 21 and interposed panel ft) to tie the may be angled differently to afford the particular overall.

surface contour desired. Also, heels 23 of clips 21 are formed with flats so the cluster of cell vertices do not terminate at a point, but form hexagonal channels 24 adapted to receive the hexagonal pins 25. Pins 25 are designed to be equal or preferably slightly larger in cross section than the channels 24, and they are inserted after the structure is completed to. post-stress the completed struc-,

ture.

Post driving of pinion rods or pins 25 into channels 24 For this to the longitudinal axis of the panel.

creates a predicted degree of inherent post-stress within the completed structural assembly, depending on the dea signed diameter. of theserods. The pinion rods raise the resonant quality of the structural assembly and thereby improve its response rate to a desired degree. Where desired the pinion rods are designed to protrude beyond the interior and exterior surfaces of the completed spinal networks, providing threaded sections 28 to connect and bolt into place'later placed cover plates, or batter plates, depending on the desired finished cross section of the finished 14 from the central clamp located in the other cell to which the particular panel ltlis common, passes through the other set of registered holes, 4?; for example, and is secured by means of nut 46 threaded onto the projecting end of the tension rod-and bearing against the other side of panel 19. It will be noted with particular reference to FIG. 4B that the rods 14 pass freelylthrough their respective registered holes in wall 10 and bearing plates 43 and 44. Thus panel It? is restrained against buckling or flexing toward the right in FIG. 4B solely by bearing on nutd, while panel ltlis restrained against buckling or flexing toward the left in FIGJtB solely by bearing on nut 45'. Accordingly tension rods 14. are stressed only in at the longitudinalmidpoints of the walls, and that the central tension rod clamps be located in the center of their respective cells, thetwo tension rods associated with each panel 1%? are displaced from each other perpendicularly Accordingly the central clamps 13 are correspondinglystaggered in this manner, as best depicted in FIG. 6.

7 Thus, with the'complete assembly of the described structural surface, comprising a complete spinal system of triangular cell 12, with the panels lltl of each cell centrally restrained by the tension rod system of three rods 14 radiating from a central clamp or cleyis 13, the structural compression load on the spinal system .isabsorbed shell. Thus these threaded rods or pins permit thespinal networks to act as their own falsework or scaffolding in the subsequent placement of laminate shells of a variety of materials. The number of laminar shells and their material are dependent on the intended function of the finished structure and the anticipated structural loads to be incurred. As an example, the basic spinal system may through the proper use of temporary batter plates be completely filled in by in situ foamed plastics, such as polyurethane or polystyrene and serving'as a hollow core for a subsequently placed interior and/or exterior laminate of reinforced concrete. Thus, use of the pinion rods as plate connection enables the design. engineer to: (1) save on excessive costs of falsework or scaifolding which is in.

most cases prohibitive in casting reinforced concrete in a warped surface; and (2) design the finished cross section of shell in several laminar layers, each laminate (a completed shell in itself) acts in juxtaposition withits counterpoised laminate. By this design concept full advantage can be taken of both the plate theory and the membrane theory in the design computations and the final design,

The central clamp structure 13 is shown in FIGS. 5,

3A and 3B. It is a three-way clevis formed of two halves 31 and 32 adapted to be bolted together by bolt 33. Each half has three sets of recesses 35A and B, 36A7and B, and 37A and B adapted to be located opposite each other and to clamp the headed ends 34 of tension rods 14 therein, as shown in FIG. 3B.

Tensionrods 14 radiate at 120 angles relative to each,

other from each central clamp 13, and'pass through respective cell bounding panels 10, as shown in FIGS. 5. 6, 4A and 4B. Each cell panel wall 10 is provided with two holes 41 and 42, one located above the other at the mid-line of the panel wall. Bearing plates 43 and 44 are positioned on either side of wall 10 with holes matching and'registering with those inpanel wall It The tension rod 14 from the central clamp 13 of one cell formed by panel '10 passes through one set of registered holes, 41

and distributed throughout the structure primarily by the a tension rod system.

It is understood that the hemispherical structure utilized to illustrate .the present invention is only for purposes of example, and that other'surface shapesand contours might be formed with thepresent-invention, requiring only that clips 21 be appropriately modified to orient the'cells in the desired c'ontoun; Also, it will :be appreciated that the triangularly shaped cells 12 are only for purposes of example; although this geometric shape .is preferred, other polygonal shapes may be employed, accordingly changing the number of tension rods per cell. In each instance it is preferred that the number of tension rods in each cluster equal thenumber of sides to the polygonal cell, and it is further preferred that the clamp orclevis forthese'rods be located .at the centrum of thecell, that therods be connected to their respective cell panels at the midpoints thereof and perpendicularly thereto, and that the polygonal shape be a regular polygon. I

In-orderbest to effect the principles of the present invention it is preferred that the flexing cell panels 10 be designed to flex at an accumulation of about ten percent of the designed structural load. Under these conditions, ninety percent of the determined .load will be, 7 supported by tension. Accordingly, the panels are contemplated as being of, relatively'light structural. materiahto take advantage of the more efiicient use'of the'major structural components being in tension.

' I 21 act merely as lacings not'ties, for' the flexing panels,

for example, and is secured by means of nut 45, threaded onto the projecting jendof the tension rod and bearing and therefore they too are'of light gage structuralmaterial. i 7

Having thus described one specific embodiment of the present invention for the purpose .of facilitating an understanding thereof, it is understood that the invention is not limited to thisembodiment, for numerous modifications andvariations will be apparent to those skilled in the .art. Accordingly such variations and modifications as are embraced by the spirit and scope of the appended claims. are contemplated as within the purview of the present invention.

What is claimed is:

it. A structural surface, co.rnprising a spinal network of interconnected flexing elements defining the bounding walls of polygonal cells, and a counterpoised tensional network therefor, comprising, assystem ,of-tension elements intercoupled witheach. other, means coupling a Similarly the clips ing elements, said coupling means including means for placing the elements of each of said pairs of tension elements in opposed tensional relationship to each other to restrainflexing of. said; flexing elementsjin opposite directions, said tension network including a tension. circuit coupling-one tension element of each'of said pairs of tension elements to the other tension element of the pair externally of the, flexing element to which such pair of tension elements isgcoupled,

' '2. A structural buildingunit comprising a polygonal cell having flexing elementsfdefining the bounding edges of the cell, a plurality of tension elements radiating from ments andextending through said flexing elements, and abutment means secured to said'tension elements and abutting said flexing elements outside the cell, said tension pair of tension elements to each of a plurality of said flexa common connection within said cell to said flexing eleelements extending through said flexing elements freely to permit flexing of said flexing elements toward said common connection, whereby said abutment means restrain said flexing elements from flexingoutwardlyfrorn said common connection.

wherein saidcell is a regular polygon, the number of tension elements equals the number of flexing elements with one tension element extending to each flexing element, saidcommon connection is located in the centrum of said cell, and said tension elements extend through said flexing elements at the midpoints of the flexing elements.

4. A structural building unit comprising two contiguous polygonal cellshaving flexing elements defining the I bounding edges of the cells and having one common flexing element defining one common bounding edge, each 'cell having a plurality of tension elements radiating from aco'mmon connection withinsuch cell to the flexing elements thereof and extending therethrough, abutment means secured to said tension elements and abutting said flexing elements outside the flrespective cell, said tension elements extending through said flexing elements freely too permit flexing movement of said flexing elements to- 3. A structural buildingunit'as' setforth' in claim '2,

ward the common connections-of said tension elements, 1

Va tension element of each cell extending through-said common flexing element, Whereby'said common flexing elementis restrained against flexing outwardly from either I of said common eonnerztions by its respectivetensio'n elements and the 'other tension elements restrain their respective flexing elements from flexing outwardly from their respective common connections.

, '5. Astructu'ral building unit as set' forth in .claim 4,

wherein said cells are regular polygons, the numberof i tension elements of each cell equals thenumber of sides of the polygon with one tension element extending to each side, said commonrconnections are located in' thecentrum of their respectivefcells, and said tensionelements extend through said flexing elements at themidpoints' ofthe flexing elements.

, 6. A structural surface, comprising a spinalnetwork ofv interconnected flexing elements defining the bounding walls of a plurality'of polygonal cells, adjacent cells having a common wall, a tension network for said cells comprising for each of said plurality of cells a plurality of tension rods radiating from a common connection within the cell to the flexing elementsthereof and passing freely through said flexing elements to the outside ofsaid;

cell, abutment means secured to each of the tension rods and abuttingsaid flexing elements on theoutside of said elements from flexing outwardly relative'to said common connection, the tension rods of at least some of the adjacent cells extending to common flexing elements therei between to provide, tension rod pairs for restraining flexing of said cornmon flexing elements in two opposite directions, and said tension network'providing a tension circuit coupling one tension rod of each of said pairs to the other tension rod of suchpair externally of the flexing element to which said pair of tension rods is concell, abutment means secured to each of the tension rods and abutting said flexing elements on the outside of the cell, whereby said abutment means restrains said flexing elements from flexing outwardly relative to said com- -mon connection, the tension'rods of at least some of the adjacent cells extending' to common flexing elements therebetween to provide tension rod pairs forrestraining flexing of said common flexing I elements in: two opposite directions. a

8. A structural surface as set forth in claim 7 wherein said polygonalcells are regular polygons.

'9. A structural surface as set forth in claim 7, wherein the number of tension rods in each cell equals the number of I sides of the cell.

10. A structural surface as set forth in said commonconnection is located in the fcentrum of the respective cell. I I 11. A structural surface as set forth in claim 7, wherein said tension rods pass through the midpoints of the respective flexing elements.

12. A structural surface as set forth in claim 7, wherein.

said-polygonal cells are regular polygons, the number or I tension rods in' 'each' cell equals the number of. sides of I the cell, the cornmon'connection is located in the centrum ofthe respective cell, and the tension rods pass tln'ough the I'nidpoints of'the respective flexing elements orthogon- .ally thereto.

13. A structural by a said tension, rod pair.'

14.,A structural surface as set forth in claim 7, and

further including means for assembling -the;encls of the flexing elements in clusters at the vertices of the cells. 15. A structural surface asset forth in claim 14, and further including means for forcing said clusters radially apart at said 'apices to post-stress the structural surface.

16. A structural surface asset forth in claim 7, and

further including a covering skin carried byv the structural surface.

cell, whereby said abutment means restrain saidflexing 7 References Cited bythe Examiner" UNITED STATES PATENTS 3,063,521 11/62 Fuller 5O 52 X' FOREIGN PATENTS 8/59 Canada. I HARRIS-ON R. MOSELEY," Primary Exam er- REINALDO P. 1 /IA( JH ADO,-Examimzr.

claim 7, wherein I surface as set forth in claim 7, wherein each'flexing element common to two cells'is restrained 

1. A STRUCTURAL SURFACE, COMPRISING A SPINAL NETWORK OF INTERCONNECTED FLEXING ELEMENTS DEFINING THE BOUNDING WALLS OF POLYGONAL CELLS, AND A COUNTERPOISED TENSIONAL NETWORK THEREFOR, COMPRISING A SYSTEM OF TENSION ELEMENTS INTERCOUPLED WITH EACH OTHER, MEANS COUPLING A PAIR OF TENSION ELEMENTS TO EACH OF A PLURALITY OF SAID FLEXING ELEMENTS, SAID COUPLING MEANS INCLUDING MEANS FOR PLACING THE ELEMENTS OF EACH OF SAID PAIRS OF TENSION ELEMENTS IN OPPOSED TENSIONED RELATIONSHIP TO EACH OTHER TO RESTRAIN FLEXING OF SAID FLEXING ELEMENTS IN OPPOSITE DIRECTIONS, SAID TENSION NETWORK INCLUDING A TENSION CIRCUIT COUPLING ONE TENSION ELEMENT OF EACH OF SAID PAIRS OF TENSION ELEMENTS TO THE OTHER TENSION ELEMENT OF THE PAIR EXTERNALLY OF THE FLEXING ELEMENT TO WHICH SUCH PAIR OF TENSION ELEMENTS IS COUPLED. 